I think I understand your point, but in judging these "identity groups" as bad, I I feel you're not giving proper weight to a practical aspect of human behavior: most people don't spend a lot of time defending other people from problems that they don't experience themselves.

I'll try to pick a group that you're more likely to feel neutral to, as an example. Let's take the Kurds. They identify as a group and defend themselves accordingly against outside groups. I think your theory is that they shouldn't identify as a group, but instead just find other people like you that think that all people are equal. Sounds good on paper maybe, but do you think that if you received an email from Kurds asking for help right now defending themselves from Turkish or Iraqi forces, you would be sending aid their way?

What identity groups have learned is that it's much easier to get sympathy and aid from people who share cultural history, beliefs, and suffer from the same problems, than some benevolent outside observer who values all lives equally, but doesn't identify with their particular group in any other way. And you're condemning them for being intelligent enough to recognize this aspect of human nature and acting accordingly.

Of course, you're correct that too strongly identifying with a group can easily lead to problems as well. One of them being that it can lead to new conflicts.

But at its heart, identity politics is usually spawned from some association for mutual benefit (mutual benefit groups can be bad or good and I can think of several mutual benefit societies that exist today that I think are "bad").

When a minority group is attacked by a majority group, it is almost inevitable that the minority group will band together, and if they don't, they will probably suffer worse. History has shown that the identity politics that you're disdaining are usually a key source of the energy required to effect a successful reform in the greater society. And this is true despite the fact that the creation of such groups also pisses off some segment of the people who aren't members of the group :-)